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ELECTRICAL PROBLEMS WITH A 1981 MODEL 10 HELP...

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I'm a new guy on this site:
Problems with my model 10's electrical system. First off the master shut off in the engine compartment. I need to replace it. Can anyone tell me what amperage I need for this. I figured more amps than the alternator puts out, but am being told not. Will a 175 amp continuous 1000 amp spike work for this and where is the best place to buy it.
Next I am having trouble with the alternator charging and also the drivers blower, booster pump, and the main heater blowers working. I have tried new relays, but didn't seem to solve the problem. Now, when it idles the bliwers stop working. If I fast idle everything seems to work. I now have the alternator putting out about 14 volts on an idle, but still doesn't operate blowers. Thank you for any and all suggestions. Bob
bob
 
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Welcome to the bus jungle!!!

Not too long ago, Hector Felip of CNF, Inc posted amongst other items a genuine replacement master switch for your Eagle on eBay. The auction ended without anyone bidding on it.

Hector’s telephone number: 972-225-1960

Good luck, Chris
Christian Berlit
El Paso, TX

He who has a why to live can bear almost any how. -- Friedrich Nietzsche
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chrisber
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Bob, perhaps this lowly neophyte to this board can provide some guiding light…

Assuming that your coach has not been victimized by “blow torch and hammer mechanics” in its past, I’d like to explain and suggest the following:

Abstract:
In an Eagle, model 10, the HVAC (for Heating, Ventilation and Air Conditioning) assembly for the driver is physically located below the driver’s seat in the spare tire compartment. The driver’s HVAC features a squirrel cage bower that is directly driven by the shaft of a sizable DC motor.

Because of the blower motor’s high current demand on the vehicle’s 12VDC electrical system, Eagle Manufacturing designed a control system that prevents catastrophic vehicle battery discharge. That is, the HVAC can only operate during travel or when the coach is parked with the main engine running.

Domain:
The electrical interfaces for the blower motor control are routed through three domains (for lack of other words): (1) Dash panel (DP), (2) Power Distribution Panel (PDP) -- front, driver side -- and (3) C&D panel above the engine compartment at the back of your coach.

Controls/Indicators:
At the driver’s dash there are four switches and an indicator light located on the outer left panel. The switches are usually labeled (1) MAIN A/C, (2) MAIN BLOWER, (3) DRIVER BLOWER, (4) DRIVER AC/HEAT and the indicator light COMP LOAD.

The control of interest here is the driver’s blower high/low speed function. The “BLOWER MOTOR Hi/LOW” switch has three connections. Wire #52 is feeds (connected to) +12V from the C&D panel above the engine compartment at the back of your coach, wire #96 is the Power Contactor Enable output and wire #165 is the Blower Motor Low Speed Enable control.

Functionality:
+12VDC power to the driver’s A/C - Heater blower motor is enabled by the “Driver’s Blower Solenoid” and fed through a heavy gauge cable #94 from the back of the bus via the front power distribution panel directly to the blower motor terminal L2. The negative terminal L1 is connecter to chassis ground. You will find that the driver’s blower solenoid is the third one from the right on the C&D panel at the rear of the bus.

The driver’s blower motor is enabled (turned on) and operated at two different speeds via a voltage (12VDC) applied to terminal (F1). This connection is provided via wire #166. However, the device that actually enables the blower is relay K5 (Voltage Regulator) located at the C&D panel. The output voltage from the Alternator/Regulator assembly is fed via wire #97 to contact 86 of the relay K5 (you can test the voltage at terminal T-97 at the C&D panel -- the relay is the second one from the right).

When K5 is enabled and contacts 30 – 87 close, 12VDC from the vehicle batteries is applied via the closed contacts of relays K7 (Main Blower Motors) -- which is also enabled by the alternator/regulator voltage -- and fed to relay K9 (Main A/C). There is a 20A fuse in line between K7 and K9. You will find that fuse between contacts 90 and 150 on the fuse board located on the right side of the C&D panel. You might as well check for continuity at this point.

K9 (Main A/C) is enabled by the voltage applied through the contact 30-87 closure of relays K5 and K7. This applies 12VDC from the vehicle batteries via the closed contacts 30-87 of K9 though a 20A fuse via terminal T-52 (on the C&D Panel). You will find the 20A fuse between contacts 88 and 52 on the fuse board located on the right side of the C&D panel as well. You can check that control voltage on terminal T-52.

From T-52, wire #52 is routed from the C&D panel at the rear of the coach all the way forward to the front PDP via its terminal T-52 the control switches “A/C-HEAT” and “BLOWER MOTOR Hi/LOW” at the driver’s dash. Either switch cannot operate if this voltage is not applied. You can check the control voltage on terminal T-52 on both the C&D panel and the PDP up front.

The relay that controls driver’s blower speed is K2, the Driver’s Blower HI/LOW relay. You’ll find it at the front PDP. It is energized by the above mentioned “BLOWER MOTOR Hi/LOW” switch. Continuity between contacts 30 and 87a runs the blower at full speed. Continuity between contacts 30 and 87 connects a resistor in series and, thus, runs the blower at reduced speed.

So, here you have it. This is the way this arcane circuitry came to fruition at the wonderful world of Eagle manufacturing ;)

Following are the steps I would pursue:

— Make sure the terminal L2 of the driver’s blower motor is properly grounded and 12VDC is applied to terminal L1 when the main engine is running.

— If not, then the driver’s blower motor is not enabled (turned on). Check this voltage at terminal T-166 at the front PDP.

— Make sure that the voltage at terminal T-97 does not fluctuate during idle. If it does, then you almost certainly have a regulator problem.

— Focus on K5 (Voltage Regulator relay). Make sure that the connections are clean and the relay energizes when 12 VDC is applied to contact 85 and 86 is properly grounded.

— Test the input voltage to relay K5 at terminal T-97 at the C&D panel -- the relay is the second one from the right).

— The Heater Boost Pumps are controlled by Relay K8. Same methodology applies here.

— Make sure the Blower HI/LOW switch is working properly. Check the control voltage for K2 (Driver’s motor) on terminal T-165.

— Check the input voltage from K2 to the blower motor on terminal T-166. You will see a voltage change onT-166 when you flip the BLOWER MOTOR HI/LOW switch.

— Make sure that a steady 12VDC is present on terminal T-96 when you flip the BLOWER MOTOR Hi/LOW switch.

— Make sure the Power Solenoid does not bounce when voltage is applied to it via terminal T-96.

Good luck -- Viel Glück -- Buena suerte -- Bonne chance,

Chris
Christian Berlit
El Paso, TX

He who has a why to live can bear almost any how. -- Friedrich Nietzsche
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Thanks Chris:

I appreciate your input. This is exactly what I am looking for. I will not be able to do anything with it for about a week, but will look into it then. I will let you know how I made out. I was looking at your post some more and realized that I am having problems with the solenoids bouncing when they are engaged. Now, how do I correct that problem. I guess I didn't understand that part of your post. To fill you in a little. I had the alternator rebuilt about a year ago and everything worked fine. I took the coach to tennessee to get some repairs done and everything was working fine when I started back. I got about 200 miles from home (This was New Years Day) and the alternator stopped charging. I then realized I had no blowers. I decided my best course was to stop for the night while it was still at freezing and dark and continue the next day in sun and daylight. Well, since that time I have been trying to solve my problem. I took the alternator back and the relay post had stopped working. I brought it back and put it on and this problem started. I took it and the regulator back off and had it checked and am told everything is fine. I just found this board a short time ago and thought I would give it a shotThanks Again Bob
bob
 
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If the relays or solenoids are chattering, maybe not enough voltage going to them. I would take you alternator and regualtor to another facility and have them check them. Maybe the orginal rebuilder missed something, dunno.

Paul
Becky & Paul Lawry
Dreamscape
1968 Eagle 01 #7443
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Chris,

You are correct on the the blower motor assembly being located under the driver in the spare tire compartment; however, this was not the case on the early Model 10 Eagle's. That change was made in late 1983 when they upgraded the entire HVAC system to the dual evaparators. Prior to late 1983, the blower motors, evaparator and heater core were located under the right hand dash and there were two small blower motors such as found in school buses.

Bob,

In the rear electrical panel you will find several square bosch relays. Locate the three marked, Voltage Regulator, Motor and Starter Protection. All three of these relays should be 6 volt relays and should have a tab sticking out of the top to indicate this. If you have a twelve volt relay in the Voltage Regulator Relay, then you need to change it to a 6 volt relay. A twelve volt relay may work intermittently, but wire number 97 white, coming from the alternator, feeds these relays with 6 volts through the coil, to ground, and then closes the contacts to allow 12 volts to flow through the relay. This then allows your alternator to come online
Daniel Lenz
Brownsville, Texas


The work of an unknown good man is like a vein of water flowing hidden underground, secretly making the ground greener.
SmoothJazz
 
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Thank you, Daniel, for enlightening me on the idiosyncratic configuration changes implemented during the Eagle Model 10 production years :D

In my travel through this fascinating window in time, I think of life more as continuous education and a giant-sized test that never really ends until the mortician throws dirt on my face. Therefore, I don’t feel foolish when I learned something new. On the contrary, I genuinely appreciate it. Neither do I feel injudicious when I honestly and candidly relay to others what I have learned thus far -- even if it exceeded the five-minute foolishness criterion ;)

Anyway, may I ask an additional question?

Does your affirmation: “Prior to late 1983, the blower motors, evaporator and heater core were located under the right hand dash” imply that the older Eagle 05 system was used in the earlier Eagle 10 buses?

Thanks,

Chris
Christian Berlit
El Paso, TX

He who has a why to live can bear almost any how. -- Friedrich Nietzsche
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That is correct.
Daniel Lenz
Brownsville, Texas


The work of an unknown good man is like a vein of water flowing hidden underground, secretly making the ground greener.
SmoothJazz
 
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You guys are absolutely correct my model 10 has the two blowers in the dash. How many volts should my system be charging. According to my meter it is charging slightly more than 14 volts on an idle. Do you think possibly I should run the regulator up a little. I was told by the alternator guy I could charge just shy of 16 volts before the batteries would start to mist. Batteries are full charged at 13.9 volts so I thought 14 was plenty. I really appreciate all of your input, because I am stuck, big time. Thanks Bob
bob
 
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Bob,

Your voltage should be 13.7 volts. If you run up the voltage to high you will do damage to your batteries.
Daniel Lenz
Brownsville, Texas


The work of an unknown good man is like a vein of water flowing hidden underground, secretly making the ground greener.
SmoothJazz
 
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